It is often desirable and necessary to sample or test a portion of a solid body, be it plant, animal or human, to determine certain characteristics and features of the whole body or a part of the larger body of tissue. Various means and apparatuses have been employed for the purpose of extracting a sample of tissue for testing and other purposes. Some of these apparatuses are the subject of certain specific patents of which applicant has knowledge. For example, U.S. Pat. No. 1,162,901 discloses an instrument for cutting cores from solid substances such as rosin from barrels. The instrument has a hollowed tube which has a rod with a cutting knife at one of its ends and a handle or means for rotating the knife to put its blade in a cutting position at the other end. The instrument is equipped with a spring biased plunger which is moved down the tube to force the piece of core out of the tube once it has been severed from the solid. The apparatus of the '901 patent must be heated to assist in the removal of the severed piece of core.
U.S. Pat. No. 3,683,892 discloses a device, comprised of a hollow extractor body, sharpened at one end, to receive a core of tissue cut by the sharpened end as the apparatus advances into the tissue body. The forward end of the sharpened extractor has a blade which is inwardly pivotal and which is responsive to the muscle tissue backflow to sever the base of the core of tissue from the surrounding tissue.
Still another means for severing a sample of tissue from a larger body has been disclosed in U.S. Pat. No. 2,493,979 in which a fruit-coring apparatus is claimed. Like the apparatus disclosed in the '901 patent, this fruit-coring apparatus also requires some pre-drilling into the body from which the sample is to be extracted, prior to the actual extraction of the sample. Thus, this apparatus, like the existing prior art apparatuses for extracting tissue samples, is rather time-consuming and may clearly result in great pain when being used to extract tissue samples from living animals, particularly humans.
The extraction of tissue samples from humans and other animals has been and is becoming even more prevalent in the diagnosis and treatment of patients for cancer, pre-malignant conditions, and/or other infections. Applicant has discovered at least one patent which is specifically directed to the application of obtaining a biopsy from human beings. This patent, U.S. Pat. No. 2,426,535, is directed to an infusion and a biopsy needle which is particularly applicable to the injection of fluid into a peripheral vein around tissue which has recently suffered extensive burns. The needle is likewise useful in extracting tissue from the same burned region.
U.S. Pat. No. 2,749,909 discloses a surgical instrument which may be used to extract a sampling of tissue from the female uterine cervix. The apparatus makes use of a conical, spiral cutting knife positioned such that the sampling of severed tissue is forced into the interior cavity of the apparatus where it is preserved until removed by the technician.
Perhaps the more growing need for having to extract samples of tissue from human beings is in the area of gynecology where a biopsy must be taken of a region of tissue for testing for cancerous or malignant cells.
Prior to taking a biopsy of tissue from the female uterine cervix, a PAP smear is usually performed. This PAP smear is done to test for the presence of abnormal cells arising from the uterus or cervix. The test is done on a sampling of cervix cells obtained by scraping a region of the cervix. The PAP smear exam may result in one of three findings: (1) benign, in which case no further test or biopsy is required; (2) precancerous, where there are cell changes which are called cervical intraepithelial neoplasia (CIN); and (3) malignant, or cancer.
In the case where there is a report of CIN from a PAP smear, a further test of a sample of the tissue from the uterine cervix is required. In obtaining this sample of tissue from the cervix, both the size and configuration of the sample is most important in arriving at an accurate examination of the sample for possible future treatment of the patient for cancer, pre-malignant conditions or other infections. In testing the sample of tissue for cancer, the actual size of the sample is of course important since the technician must have a large enough piece of tissue to make appropriate tests. But, even more important than the actual size of the sample of tissue is its configuration, since it is desirable from the technicians point of view to have a non-distorted sample of tissue so that the actual stage of development of the cancer or pre-malignant cells, or rather, how much the normal cell maturation process has been distorted and how far along the development of the immature cells has progressed, must be determined from the tissue sample being tested in order that future treatment of the detected disease may be as effective as possible.
There have been a number of prior art apparatuses for use in obtaining a biopsy of tissue from human beings from areas such as the female cervix. One such apparatus is a biopsy punch which is used primarily for extracting samples of tissue by surgical specialists and, in some cases, it is utilized in the area of dermatology for the same purpose. Despite this apparatus' possibly obvious application in the area of extracting samples from the cervix to test for cancer, it leaves much to be desired because the device, like the other prior art apparatuses, has minimal control over the actual size and shape of sample which is extracted. This biopsy punch, and other apparatuses which have been used for extracting tissue samples primarily from humans, and, more particularly from the female cervix, operates more or less on the principle of a pair of household scissors. That is, the apparatus, first of all, is manually operated, and, further, it depends on two pieces of the apparatus being pivoted about a lever or pivotal point to come together after being forced against the body of tissue to sever a sampling of the tissue body. With these types of apparatuses, it is, for the most part, impossible to control the actual size and, more importantly, the actual shape of the sample. The use of this and other biopsy punch apparatuses will inevitably result in irregularly shaped samples of tissue which may result in inaccurate test results. Quite clearly, it goes without saying that the need for as accurate a test result as possible in an area so vital to human beings as the test for cancer is of the utmost importance, for the result of such tests may clearly mean the difference between life and death.